Physics, 그런데 이제 Sling-shot을 곁들인。
\text{Constants}\\
C_d=0.47\, \text{공의 항력계수}\\
\rho=1.293 [kgm^{-3}]\, \text{공기의 밀도, 1기압, 섭씨 25도}\\
D=8730 [kgm^{-3}]\, \text{Brass, 섭씨 0도}//
\text{Physical Variables}\\
L_t=0.7 [m]\, \text{잡아당기는 거리}\\
t_r=0.15 [s]\, \text{반응속도, 프로게이머 기준}\\
V_c=100 [ms^{-1}]\, \text{눈을 관통하기 위한 접촉 시점의 요구 속력}\\
r_e=0.012 [m]\, \text{안구의 반지름}\\
r_b=r_e\, \text{공의 반지름}
\text{Equations}\\
\text{새총 방정식}\\
\varepsilon =\frac{L}{2} \; \therefore \frac{d\varepsilon}{\varepsilon}=\frac{x}{L}=\frac{dx}{L} \quad d\varepsilon=\frac{\varepsilon}{L} dx \qquad \dot{\varepsilon} = \frac{\varepsilon}{L} \dot{x} \\
E^k_b=\frac{1}{2} M_b \dot{x}^2 \\
E^k_s=\frac{1}{2} \int_0^L \sigma d\varepsilon \left( \frac{\varepsilon}{L} \dot{x} \right) ^2 \, dx=\frac{1}{6} \sigma L \dot{x}^2=\frac{1}{6}M_b \dot{x}^2\\
E^k = \frac{1}{2} \left( M_b + \frac{1}{3} M_s \right) \dot{x}^2\\
E^p=\frac{1}{2}kx^2\\
E=\frac{1}{2} \left( M_b + \frac{1}{3} M_s \right) \dot{x}^2 + \frac{1}{2} k x^2\\
\frac{dE}{dx} = 0 =\frac{d}{dx} \left\{ \left( \frac{1}{2} M_b+\frac{1}{6} M_s \right) \dot{x}^2 + \frac{1}{2} k x^2 \right\} = \left( M_b+ \frac{1}{3} M_s \right) \ddot{x} + kx \qquad \ddot{x}=\frac{kx}{M_b + \frac{1}{3} M_s } \\
v = \int_0^t \ddot{x} \, dx = \frac{k}{M_b+\frac{1}{3} M_s} \cdot \frac{1}{2} t^2 \\
\text{항력 방정식}\\
F_A=-\frac{1}{2}C_d \rho A_b v^2\\
a_A= -\frac{-3 C_d \rho }{8Dr} v^2\\
\dot{x} = \int_0^T - \frac{3 C_d \rho }{8Dr} \dot{x}^2 t dt + v_0 =-\frac{3 C_d \rho }{8Dr} \dot{x}^2 +v_0 \\
v_0 = \frac{3 C_d \rho }{8Dr} v^2 + v